IMHO 16x20 is too big for an 8x10. You are spending a lot of extra $$ for that big piece of mat board. 11 x14, or 13 x 15 is probably a good compromise. If you go 13 x 15, then all the borders are 2.5" making the overmat cuts a simple process. But as others have said, it depends on the strength of the image. Personally, I think huge-ass mats are pretentious -- look at what is used in art galleries that are showing prints by Adams, weston, and others. No big-ass overmats. That's just MY opinion.